5. Figure 27-02a
FG27_02A.JPG
Title: The Male Reproductive System, Part II
Notes: Diagrammatic anterior view of the gonads, external genitalia, and associated structures in a male.
Keywords: reproductive system, male, penis, scrotal septum, scrotum, testis, spermatic cord, artery, testicular, vas deferens, epididymis, inguinal ligament, cremaster muscle, perineal raphe, tunica vaginalis, genitofemoral nerve, testicular artery, inguinal canal

6. Figure 27-05c FG27_05C.JPG Title: The Seminiferous Tubules
Notes: (a)Seminiferous tubules in sectional view. (b)Meiosis in the testes. (c)Spermatogenesis within one segment of a seminiferous tubule. (d)Blood-testis barrier in the wall of a seminiferous tubule.
Keywords: testes, meiosis, spermatogonia, spermatocytes, spermatids, spermatozoa, haploid, diploid, interstitial cells, connective tissue capsule, fibroblast, sustentacular cells

7. Figure 27-05b FG27_05B.JPG Title: The Seminiferous Tubules
Notes: (a)Seminiferous tubules in sectional view. (b)Meiosis in the testes. (c)Spermatogenesis within one segment of a seminiferous tubule. (d)Blood-testis barrier in the wall of a seminiferous tubule.
Keywords: testes, meiosis, spermatogonia, spermatocytes, spermatids, spermatozoa, haploid, diploid, interstitial cells, connective tissue capsule, fibroblast, sustentacular cells

8. Figure 27-09c FG27_09C.JPG Title: The Penis
Notes: (a)Frontal section showing penis structure. (b)Cross-section of penis; three masses of erectile tissue. (c)Lateral, oblique view of penis; orientation of erectile tissues. (d)Cross-section of penis near its base.
Keywords: penis, frontal, prepuce, glans, external urethral meatus, penile urethra, corpus cavernosum, corpus spongiosum, bulbourethral ducts, root, bulbourethral gland, ductus deferens, seminal vesicle, prostate, scrotum

9. The Penis Parts of the penis glans penis = head of the penis
penile shaft = body of the penis
corona glandis = rounded ridge at back end of the glans penis
penile prepuce (foreskin) = not present in circumcised men; small glands under the foreskin secrete oil which when mixed with skin cells produces smegma

10. The Penis
Retraction of the foreskin to remove smegma with soap and water is important to prevent bacterial infection.
Penile shaft contains three cylindrical spongy tissue masses, two of which are the corpus
cavernosa on the top of the shaft and the third is the corpus spongiosum on the bottom of the shaft
(through which the urethra runs).

11. The Penis
Length of non-erect (flaccid) penis is usually between 8.5 to 10.5 cm (3.3 to 4.1 inches) with an average of 9.5 cm (3.7 inches)
The average length of an erect penis is 16 cm (6.3 inches) with a range of 12 cm to 23.5 cm
(4.7 to 9.2 inches).
Average circumference of an erect penis at its thickest point is 13.2 cm (5.2 inches)
There is no correlation between skeletal system make-up and penis size. A smaller non-erect
penis will enlarge more during erection than a larger non-erect penis.

12. Figure 27-13 FG27_13.JPG Title: Meiosis and Ovum Production
Notes: A diagrammatic view of meiosis and ovum production.
Keywords: meiosis, ovum, mitosis, oocyte, polar body, gamete

13. Figure 27-20a FG27_20A.JPG Title: The Female External Genitalia
Notes: (a)Inferior view of female perineum. (b)Diagrammatic frontal section; internal and external reproductive structures.
Keywords: external genitalia, female, perineum, clitoris, labia, anus, vaginal entrance, vestibule, urethral opening, vagina, levaor ani, urogenital diaphragm, hymen location, fornix

14. The Clitoris
The clitoris lies at the junction of the upper of the two labia minora above the urethral opening.
The average length is about 2.5 cm (1 inch) with an average diameter of ½ inch. There is much individual variation with regard to size and shape.

15. The Clitoris
The clitoral shaft (similar to the penile shaft) contains a pair of corpora cavernosa spongy
tissue cylinders. There is no corpus spongiosum in the clitoris.
This tissue is the labia minora in females (same embryological origin as the corpus spongiosum in the penis).
The clitoral glans (head or tip) is covered by the clitoral prepuce (similar to the foreskin of the
penis).

16. The Clitoris
The clitoris is rich in deep pressure and temperature receptors with only few touch receptors.
Plays an important role in sexual arousal. During the plateau phase the deep pressure
receptors are important for detecting stimulation of the retracted clitoris through the clitoral hood and mons.

23. Figure 27-09c FG27_09C.JPG Title: The Penis
Notes: (a)Frontal section showing penis structure. (b)Cross-section of penis; three masses of erectile tissue. (c)Lateral, oblique view of penis; orientation of erectile tissues. (d)Cross-section of penis near its base.
Keywords: penis, frontal, prepuce, glans, external urethral meatus, penile urethra, corpus cavernosum, corpus spongiosum, bulbourethral ducts, root, bulbourethral gland, ductus deferens, seminal vesicle, prostate, scrotum

24. The Penis Parts of the penis glans penis = head of the penis
penile shaft = body of the penis
corona glandis = rounded ridge at back end of the glans penis
penile prepuce (foreskin) = not present in circumcised men; small glands under the foreskin secrete oil which when mixed with skin cells produces smegma

25. The Penis
Retraction of the foreskin to remove smegma with soap and water is important to prevent bacterial infection.
Penile shaft contains three cylindrical spongy tissue masses, two of which are the corpus
cavernosa on the top of the shaft and the third is the corpus spongiosum on the bottom of the shaft
(through which the urethra runs).

26. The Penis
Length of non-erect (flaccid) penis is usually between 8.5 to 10.5 cm (3.3 to 4.1 inches) with an average of 9.5 cm (3.7 inches)
The average length of an erect penis is 16 cm (6.3 inches) with a range of 12 cm to 23.5 cm
(4.7 to 9.2 inches).
Average circumference of an erect penis at its thickest point is 13.2 cm (5.2 inches)
There is no correlation between skeletal system make-up and penis size. A smaller non-erect
penis will enlarge more during erection than a larger non-erect penis.

27. Figure 27-13 FG27_13.JPG Title: Meiosis and Ovum Production
Notes: A diagrammatic view of meiosis and ovum production.
Keywords: meiosis, ovum, mitosis, oocyte, polar body, gamete

28. Figure 27-20a FG27_20A.JPG Title: The Female External Genitalia
Notes: (a)Inferior view of female perineum. (b)Diagrammatic frontal section; internal and external reproductive structures.
Keywords: external genitalia, female, perineum, clitoris, labia, anus, vaginal entrance, vestibule, urethral opening, vagina, levaor ani, urogenital diaphragm, hymen location, fornix

29. The Clitoris
The clitoris lies at the junction of the upper of the two labia minora above the urethral opening.
The average length is about 2.5 cm (1 inch) with an average diameter of ½ inch. There is much individual variation with regard to size and shape.

30. The Clitoris
The clitoral shaft (similar to the penile shaft) contains a pair of corpora cavernosa spongy
tissue cylinders. There is no corpus spongiosum in the clitoris.
This tissue is the labia minora in females (same embryological origin as the corpus spongiosum in the penis).
The clitoral glans (head or tip) is covered by the clitoral prepuce (similar to the foreskin of the
penis).

31. The Clitoris
The clitoris is rich in deep pressure and temperature receptors with only few touch receptors.
Plays an important role in sexual arousal. During the plateau phase the deep pressure
receptors are important for detecting stimulation of the retracted clitoris through the clitoral hood and mons.

46. Infertility Rates and Woman’s Age in American Women
Age Infertility Rate %
25 to %
30 to %
35 to %
Due to increase in chromosomal abnormalities due to eggs arrested in Prophase I of Meiosis I

47. Menopause
In vertebrates, only human females (African Elephants, Pilot Whales & Chimpanzees) live a significant portion of their lives postreproductively
Average age of Menopause in U.S. = 52 years old
Normal age range for menopause is 45 to 55
Nulliparous women tend to have an earlier menopause than women who were pregnant
Use of the pill tends to delay menopause

49. Stages of Menopause
1. Perimenopause begins several years before menopause, when the ovaries gradually produce less estrogen. Perimenopause lasts up until menopause, the point when the ovaries stop releasing eggs. In the last one to two years of perimenopause, the decrease in estrogen accelerates. At this stage, many women experience menopause symptoms.
2. Menopause is the point when a woman has her last menstrual period. At this stage, the ovaries have stopped releasing eggs and producing most of their estrogen. Menopause is diagnosed when a woman has gone without a period for 12 consecutive months.
3. Postmenopause is the time after menopause. During this stage, menopausal symptoms, such as hot flashes ease for most women. However, health risks related to the loss of estrogen increase as the woman ages.

51. Symptoms of Peri/Menopause
Irregular Menstrual Periods
Hot Flashes
Night Sweats
Disturbed Sleep Patterns
Vaginal Dryness
Shrinkage of Genital Tissue
Dry Skin
Frequent Minor Vaginal Infections

52. Menopause Characteristics
Menopausal Symptoms
Decrease in estrogen from ovaries
Significant decrease in progesterone once she stops ovulating
During perimenopause = anovular cycles with menstruation but no ovulation
Increased blood levels of LH and FSH due to loss of negative feedback (4 – 10 X)

55. Premature Menopause
Premature menopause can be the result of genetics, autoimmune disorders or medical procedures. Occurs in about 1 in 100 women.
Premature Ovarian Failures - Normally, the ovaries produce both estrogen and progesterone. Changes in the levels of these two hormones occur when the ovaries, for unknown reasons, prematurely stop producing eggs. When this happens before the age of 40, it is considered to be premature ovarian failure. Unlike premature menopause, premature ovarian failure is not always permanent.
“Induced" Menopause - occurs when the ovaries are surgically removed for medical reasons, such as uterine cancer or endometriosis. Induced menopause can also result from damage to the ovaries caused by radiation or chemotherapy.

56. Complications due to Menopause
The loss of estrogen associated with menopause has been linked to a number of health problems that become more common as women age.
After menopause, women are more likely to suffer from:
Osteoporosis (brittle-bone disease).
Heart Disease
Poor bladder and bowel function.
Poor brain function (increased risk of Alzheimer's disease).
Poor skin elasticity (increased wrinkling).
Poor muscle power and tone.
Some deterioration in vision, such as from cataracts (clouding of the lens of the eye) and macular degeneration (breakdown of the tiny spot in the center of the retina that is the center of vision).
There are a number of treatments to consider that can reduce the risks associated with menopause.

58. Pregnancy and Menopause
Woman’s fertility more dependent on how close she is to menopause than her age
Most infertility due to loss of pre-embryos or implanted embryos
After 40 = more affected by ovarian function and failure to ovulate
After age 42 = less than 10% chance of pregnancy
Decline in egg quality precedes the decline in egg quantity

59. Evolution of Menopause
Why did Menopause evolve in Humans?
Limits ovulation of abnormal oocytes
Younger mothers tolerate pregnancy, birth and childcare stresses better
Higher risk of death in older mother and thus risk her older children
Kin selection = “grandmother hypothesis” = menopausal women can help in childcare and her daughter could have more children = increases grandmother’s evolutionary success

60. Andropause = “male menopause”
Nothing like menopause; many men father children into their nineties
Due to decrease in androgen (testosterone) production as a man ages = about 1% per year after age 40
Due to decrease in ability of testes to respond to LH and FSH
Decreases in:
Ability to achieve and maintain erections
Facial hair growth; voice pitch may rise
Shrinkage of penis and scrotum
Muscle mass
Bone density = increased risk of osteoporosis
Sex drive (libido)
May lead to depression and irritability due above symptoms.